Good approach, though i would disagree with the statement that mathy
stuff with numbers is best in spreadsheets. I've wasted enough time
scrubbing spreadsheet cells one by one to see the hidden formulas to
find the one with the error to decide that spreadsheets are unsuitable
for anything except quick exploratory analysis that will later be
transferred to a robust environment (i.e., R). This is a consequence of
the broken design model of spreadsheets.
Specific programs (*cough* Excel *cough*) also have nasty bugs in their
math functions (that have been known for years but never fixed) that
yield mathematically invalid results when presented with certain
atypical inputs. Just say no to spreadsheets.

Well of course programming beats everything :)
Even scripting where you can choose the proper tools for a pipe has its
advantages. I was only covering the proper use of applications. Anything
real involved came to our desk anyway.